file extension Windows/OS2/Apple/Unix/Dos

File ExtensionsWindows/OS2/Apple/UNIX

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R = Fortran preprocessor Source RatFor
R = Macintosh Resource similar to RC
R = Paradox file
R = Pegasus Mail resource
R#+A = (MAC FILE TYPE) RagTime Classic text file
R#+D = (MAC CREATOR CODE) Rag Time 3
R00 = Norton Ghost rar file
R01 = Norton Ghost rar file
R01 = RAR compressed files from a multi-volume archive
R02 = Norton Ghost rar file
R02 = RAR compressed files from a multi-volume archive
R03 = Norton Ghost rar file
R04 = Norton Ghost rar file
R05 = Norton Ghost rar file
R06 = Norton Ghost rar file
R07 = Norton Ghost rar file
R08 = Norton Ghost rar file
R09 = Norton Ghost rar file
R0C = Fax cover
R0F = Fax document
R0H = Fax header
R10 = Norton Ghost rar file
R11 = Norton Ghost rar file
R12 = Norton Ghost rar file
R13 = Norton Ghost rar file
R14 = Norton Ghost rar file
R15 = Norton Ghost rar file
R16 = Norton Ghost rar file
R17 = Norton Ghost rar file
R18 = Norton Ghost rar file
R19 = Norton Ghost rar file
R20 = Norton Ghost rar file
R21 = Norton Ghost rar file
R22 = Norton Ghost rar file
R23 = Norton Ghost rar file
R24 = Norton Ghost rar file
R25 = Norton Ghost rar file
R26 = Norton Ghost rar file
R27 = Norton Ghost rar file
R28 = Norton Ghost rar file
R29 = WinRAR open with: "%ProgramFiles%\winrar\WinRAR.exe" "%1"
R29 = WinRAR open with: "%ProgramFiles%\WinRAR\WinRAR.exe" "%1"
R29 = WinRAR open with: "%ProgramFiles%\xp\WinRAR\WinRAR.exe" "%1"
R2D = Reflex 2 Data
R2LANG = Rainlendar2Lang open with: %Root%\Tools\Rainlendar2\Rainlendar2.exe -i "%1"
R2LIC = Rainlendar2License open with: %Root%\Tools\Rainlendar2\Rainlendar2.exe -i "%1"
R2SKIN = Rainlendar2Skin open with: %Root%\Tools\Rainlendar2\Rainlendar2.exe -i "%1"
R2SKIN-ADDON = Rainlendar2SkinAddon open with: %Root%\Tools\Rainlendar2\Rainlendar2.exe -i "%1"
R2V3 = (MAC FILE_TYPE) Streamline
R3T = Mime: text/vnd.rn-realtext3d
R8 = Raw graphics (one byte per pixel) plane one (PicLab)
R8 = Red channel image data (24bit 3D animation) (Cubicomp PictureMaker)
R81 = Game: Ms flight Texture file
R82 = Game: Ms flight Texture file
R8? = Microsoft Word for DOS/WordPerfect Font
R8L = LaserJet Landscape Font
R8P = Intellifont Pcl 4 bitmap font file
R?? = RAR Compressed File (?? can be 01 to 99)
RA = Mime: application/x-pn-realaudio
RA = Mime: audio/vnd.rn-realaudio
RA = Mime: audio/x-pn-realaudio
RA = Mime: audio/x-pn-realaudio-plugin
RA = Mime: audio/x-realaudio
RA = RealAudio
RA = Remote Access data file
RAC = Subtitling file format
RAD = Radiance image file
RAD = Reality AdLib Tracker 2-op FM music
RAF = Illum src Rk file
RAM = Mime: application/x-pn-realaudio
RAM = Mime: audio/x-pn-realaudio
RAM = Mime: audio/x-pn-realaudio-plugin
RAM = Real Audio sound
RAM = RealMedia
RAO = ReadAllOver (YOUniverse)
RAP = Magix Musstu Rap file
RAR = Mime: application/rar
RAR = RAR-compressed archive
RAS = Mime: application/x-cmu-raster
RAS = Mime: image/cmu-raster
RAS = Mime: image/x-cmu-raster
RAS = Sun Raster bitmap image, UNIX
RAST = Mime: image/cmu-raster
RAST = Sun Raster bitmap image, UNIX
RAT = "Recreational Software Advisory Council" (RSACI.RAT)
RAT = RATS datafile
RAV = Game: fifa 2001 data enviro file
RAW = Bitmap picture
RAW = HSI Raw image format
RAW = PCM Signed Raw Sound File
RAW = Raw File Format (bitmap)
RAW = RAW grayscale/24-bit RGB bitmap image
RAW = RAW sound file
RAW = RealAudio sound; see RA
RAX = Image File
RAY = Rayshade
RB = (fuzzy rule based definition)see below
RB = Mime: application/x-rocketbook
RB1 = R:Base Data File
RB2 = R:Base Data File
RB3 = R:Base Data File
RBD = (fuzzy rule based definition)fuzzy system modelling environment in ebnf-notation
RBF = Rbase datafile
RBH = RoboHelp Configuration
RBI = Adressmn file
RBM = Propellerhead ReBirth Modulation v2.0
RBS = RealiMation 3D Object
RC = Emacs configuration record
RC = ResourCe Script "Borland C++"
RC = ResourCe Script "Ms C, C++"
RC = ResourCe Script "Resource WorkShop"
RC2 = Ms Developer Studio not editable resources
RC3 = Vc98 resources file
RC_ = Winhelp file (compressed)
RCD = Formula 1 car race 2001 Season01 Drivers file
RCE = Ntgraph Gui Ctl3d file
RCF = "Audiogalaxy Rhapsody" storage file
RCF = Game: colin Mc Rae car race Configuration file
RCG = Netscape newsgroup file (netsc.rcg)
RCL = EasyCDCreator.Document.8 open with: "%Applications%\WinonCD8\Creator Classic\Creator8.exe" "%1"
RCP = Recomposer's MIDI Sequencer Music File
RCT = Mime: application/prs.nprend
RCT = Ms Developer Studio resource template
RCV = Resource Compiler; Resource script
RD1 = DATAIR Retirement Document System Data File
RD2 = DATAIR Retirement Document System Custom Text File
RD3 = Ray Dream Designer 3 graphics
RD3A = (MAC FILE_TYPE) Ray Dream Designer
RD3F = (MAC FILE_TYPE) CorelDraw 3D File
RD3F = (MAC FILE_TYPE) Ray Dream 3 Mode
RD4 = Ray Dream Designer Graphics
RD4A = (MAC FILE_TYPE) Ray Dream Studio
RD4F = (MAC FILE_TYPE) Ray Dream 4 Model
RD5 = Ray Dream Designer Graphics
RDB = Netscape Communicator Aim file
RDC = "IBM Voice Type" languages scripts Data file
RDEF = Geoworks UI resource file (old)
RDEV = (MAC FILE_TYPE) Chooser Device
RDF = Compiled UIC source code (Geoworks UI Compiler)
RDF = Resource Description Framework file
RDI = Device independent bitmap file (RIFF RDIB format)
RDL = Paradox
RDLC = VisualStudio.rdlc.9.0 open with: "%ProgramFiles%\Microsoft Visual Studio 9.0\Common7\IDE\devenv.exe" /dde Content Type application/xml
RDOFF = Programming
RDP = RDP.File special configuration file for application(binary format)
RDS = Ray dream 3d amination
RDV = Ntgraph Borland C 32 file
RDX = Database; Borland Reflex
REA = Doc Free Geocom file
REA = readme text file
README = text file
REC = ARCSERVE archivation protocol
REC = EpiInfo datafile
REC = Sprint record
REC = Windows Macrorecorder macro
RED = Clarion Modula-2 path info
RED = Rational Rose module diagram
REF = Cross-reference
REF = Reference; (generic name)
REG = Registration information/key for W95/98...
Regi = (MAC FILE_TYPE) Kagi Register Program
REGS = (MAC FILE_TYPE) Netscape Registry
RELS = xmlfile open with: "%ProgramFiles%\Common Files\Microsoft Shared\OFFICE12\MSOXMLED.EXE" /verb open "%1" ContentType application/
RELS = xmlfile open with: "%ProgramFiles%\Gemeinsame Dateien\Microsoft Shared\OFFICE12\MSOXMLED.EXE" /verb open "%1" ContentType application/
RELS = xmlfile open with: "%ProgramFiles%\Internet Explorer\iexplore.exe" -nohome ContentType application/
REM = REMarks
REN = Gen. renamed file
RENDERMAN = Pixar RenderMan 3.1 specification
reno = (MAC FILE_TYPE) Apple Guide
REP = AAICWpro autoresponder file
REP = Mime: application/vnd.businessobjects
REP = Qwk reader REPly file
REP = REPort file made by several programs
REP! = (MAC FILE_TYPE) Replica
REPORT = Report chemical modeller output file
REQ = REQuest
RES = Compiled resource Ms C, C++
RES = Compiled Resources Borland C++
RES = XBoard resign conferences file
RESMONCFG = Diagnostic.Resmon.Config open with: %SystemRoot%\system32\perfmon /res /load "%1"
RET = Basic Realizer Careal Caret Samples file
REV = FrameMaker document; see MIF
REV = Geoworks revision file
REV = Revolution stack
REX = Oracle report definition
REX = PharLab executable file (old format)
REX = Rexx language source code
REXX = Mime: text/x-script.rexx
REXX = Rexx language source code
REZ = Resource file
RF = Bitmap image (Raster File)
RF = FrameMaker document
RF = Mime: image/vnd.rn-realflash
RF = RealFlash Clip
RFB = RoboForm
RFD = RecogniFORM Form Definition
RFG = RFG Integrator System Database
RFH = RFG Integrator Householding Database
RFM = Rich music format
RFT = Document; IBM DisplayWrite RFT-DCA
RFX = Modula M2sds file
RG = Bitmap image (1bit B&W 4bit CMYK) (Raster Graphics format)
RGB = Bitmap picture
RGB = Mime: image/x-rgb
RGB = SGI RGB files (Silicon Graphics)
RGB = Silicon Graphics Raw Red, Green and Blue bytes bitmap image
RGB = VideoCraft GIF
RGBA = Raw Red, Green, Blue and intensity bytes
rgDB = (MAC FILE_TYPE) Adobe Registration DB
RGE = Inno Setup Registry Entries file
RGH = ZZ RouGH image/tbv
RGI = RealArcade Game Installer (not secured)
RGN = DDTitle.Project open with: %ProgramFiles%\DDTITLE\ddtitle.exe "%1"
RGN = DDTitle.Project open with: DDTITLE
RGP = RealArcade Game Package
RGS = Script for Windows Registry
RGX = Symbol tables etc. info (ReaGeniX code generator)
RH = Resource Header (Borland C++/Visual C++)
RI = Lotus 1-2-3 data
RIA = Alpharel Group IV bitmap
RIB = 3d graphics (3D Reality)
RIB = 3d graphics (Renderman Interface Bytestream)
RIC = Ricoh fax
RICHMEDIA = Norton Guides file
RIF = Recource Interchange File Format bitmap image
RIFF = (MAC FILE_TYPE) Painter Image
RIFF = Recource Interchange File Format bitmap image
RIP = Quincy program crash report
RIP = Remote Access graphics
RIP = Telegrafx Remote Imaging Protocol (Maximus 3.0)
RIR = Spaceward Satori family native (Windows)
RIS = Hdf Zlib file
RIS-RM8 = risfile-rm8 open with: %ProgramFiles%\GEMEIN~1\Risxtd\Risweb32.exe "%1" Content Type application/x-Research-Info-Systems-RM8
RISCOS = (makefile for )riscos file
RIX = Bitmap image (RIX Softworks Paint Tool ColoRIX file)
RJS = Mime: application/vnd.rn-realsystem-rjs
RJS = RealSystem Skin
RKV = RKIVE compressed file archive
RL$ = Basic Realizer Disk1 file
RL1 = Descent1 Registered Level File
RL2 = Descent2 Registered Level
RL4 = Bitmap image
RL8 = Bitmap image
RLA = Alias/Wavefront bitmap image
RLB = Alias/Wavefront bitmap image
RLB = Harvard Graphics Win data
RLC = Bitmap image (Run Length RLC file)
RLC = Mime: image/
RLC2 = Image Systems RLC2 Graphic image format
RLD = Norton Commander 5.0 temporary file
RLE = Intergraph Format image format
RLE = Run Length Encoded bitmap image
RLE = same as bmp
RLE = Utah raster bitmap image
RLF = Mime: application/x-richlink
RLF = RichLink compiled format
RLG = Regcleaner Languages file
RLL = Basic Realizer Careal file
RLO = Basic Realizer Careal Lib file
RLV = Basic Realizer Careal Clipart file
RLZ = Realizer source code file (CA-Realizer)
RM = Mime: application/vnd.rn-realmedia
RM = Mime: application/x-pn-realaudio
RM = Mime: audio/x-pn-realaudio
RM = Mime: audio/x-pn-realaudio-plugin
RM = RealMedia
RMAP = Real Pool Image
RMD = Microsoft RegMaid document
RME = Sb_awe keys file
RMF = Beatnik Rich Music Format
RMF = RealMedia File
RMI = MIDI-sequention music (RIFF RMID format)
RMI = Mime: audio/mid
RMJ = rmjfile special configuration file for application(binary format)
RMK = Makefile (CA Clipper RMake)
RMM = Mime: audio/x-pn-realaudio
RMM = RealMedia audio (RealPlayer)
RMP = Mime: application/vnd.rn-rn_music_package
RMP = Mime: audio/x-pn-realaudio
RMP = Mime: audio/x-pn-realaudio-plugin
RMP = RealAudio audio file
RMX = Mime: application/vnd.rn-realsystem-rmx
RMX = RealJukeBox MP3 File
RN = Xpl program (Nota Bene)
RND = AutoCAD Autoshade rendering slide
RND = Mime: application/prs.nprend
RND = PGP Random Seed
RNG = Mime: application/ringing-tones
RNG = Mime: application/
RNG = Nokia Communicator ringing tone
RNK = Dial-up shortcut
RNL = GTX runlength encoded bitmap graphics
RNO = Runoff file (VAX)
RNX = Mime: application/vnd.rn-realplayer
RNX = RealPlayer audio
ROB = Dllbackup microsoft artgalary file
ROCKWELL = rockwell (modem) file
ROFF = Mime: application/x-troff
ROFF = Unformatted manual page (Roff/nroff/troff/groff)
rohd = (MAC FILE_TYPE) Read-Only Disk Image
ROL = Adlib syntesized music (Roland)
ROM = Read Only Memory image (emulators/AONs)
RonA = (MAC FILE_TYPE) Graphing Calculato
ROT = Rotater 3D image
ROV = Rescure Rover game data
ROXIO = RoxioCentral.File open with: "%ProgramFiles%\Gemeinsame Dateien\Roxio Shared\Roxio Central\Main\Roxio_Central.exe" "%1"
ROY = TrueType
RP = Mime: image/vnd.rn-realpix
RP = Rainbow Painter image format
RP = RealPix image
RP1 = Database Text; R&R report file
RP3 = Game: need for speed car race file
RPB = CP Backup report
RPBM = Portable Bitmap image format
RPC = ACT! 2.0 Report
RPD = Database; Ashton Tate RapidFile
RPF = AutoCAD pattern
RPG = The RPG programming language
RPGM = Portable Image
RPI = "solid free form fabrication" flexible file format
RPJ = RealSlideshow Project
RPL = Document (Replica)
RPL = RePLy message
RPM = Linux Package Manager( installing, uninstalling, verifying, querying, and updating software packages)
RPM = Mime: application/x-pn-realaudio
RPM = Mime: audio/x-pn-realaudio-plugin
RPM = Mime: audio/x-pn-RealAudio-plugin
RPM = RealAudio plugin
RPM = RunPaint (Multicolor) image format
RPN = ACT! 2.0 Report
RPNM = Portable Image image format
RPPM = Portable Image
RPR = "IBM Voice Type" languages Vocabels file
RPT = Microsoft Visual Basic Crystal Reports file
RPV = Listlabl file
RQY = MS Excel OLE DB Query File
RRF = Musicmatch Jukebox file
RRS = Road Rash Save File
RS = Data file (Amiga Resource/Reassembler)
RS = Sun Raster Images image format
RS6000 = Rs 6000 (make-)file
RS_ = Resource fork of a Macintosh file (Mac-ette)
RSA = PKCS7 signature, MD5 + RSA
RSB = Red Storm Bitmap. RSB plugins for Photo or Paint Shop
RSC = Compiled ReSourCe(s)
RSD = Roland sound file
RSD = Scanner Recognita file
RSDF = rsdf open with: "%Root%\cryptload1.6\CryptLoad.exe" "%1"
RSDF = rsdf open with: "%Root%\Tools\CryptLoad_1.0.4\CryptLoad.exe" "%1"
RSET = (MAC FILE_TYPE) Extensions Manager Set
RSF = Mediafour MacDrive Macintosh Resource Fork
RSG = Compiled resource header (EPOC)
RSK = Risk project (RiskMan)
RSL = Paradox (used with FSL)
RSL = PC Tools for Win ReSource Library
RSM = Mime: model/vnd.gdl
RSM = Mime: model/
RSM = Resume file (WinWay Resume Writer)
RSML = Mime: application/vnd.rn-rsml
RSML = RealSystem ML File
RSN = Propellerhead Reason Audio File
RSP = Linker response file (generic)
RSRC = icnsfile open with: "%ProgramFiles%\Axialis\IconWorkshop\IconWorkshop.exe" %1
RSRC = (MAC FILE_TYPE) Resource File
rsrc = (MAC FILE_TYPE) Resource Filek ImageBrsrc
RSRC = ReSouRCe rsrc files Type "RSRC" Creator "RSED" (MAC)
RSS = Resource source file (EPOC)
RsSc = (MAC FILE_TYPE) Claris Resolve Script
RST = "IBM Voice Type" languages scripts Data file
RSX = data base file (from ????)
RT = Mime: text/richtext
RT = Mime: text/vnd.rn-realtext
RT = Rich Text
RT = Behemot 3d Scene Files
RT$ = Ntgraph Visual c wizzard file
RT_ = Winhelp file (compressed)
RTA = "IBM Voice Type" languages Vocabels file
RTB = Behemot binary 3d Scene Files
RTC = Rescue Me file
RTCP = Realtime Transport Control Protocol
RTD = Ragtime examples render file
RTE = Mime: x-lml/x-gps
RTF = Mime: application/msword
RTF = Mime: application/rtf
RTF = Mime: application/x-rtf
RTF = Mime: text/richtext
RTF = Mime: text/rtf
RTF = Rich Text Format document
RTF_ = (MAC FILE TYPE) RTF produced by Microsoft Word (PC ext: RTF)
RTF_ = (MAC FILE_TYPE) Rich Text Format Filetrtf
RTFD = RTF-Packet (NeXT)
RTG = Mime: application/metastream
RTH = ANSYS Results
RTK = RoboHelp Configuration
RTL = Bitmap image (HP Raster Transfer Language) (HP colour printers)
RTL = Norton Utilities runtime library
RTL = Text file
RTM = Real Tracker music module (MOD) file
RTP = MS patch file (usually MS VC++)
RTP = Software update file (.RTPatch)
RTR = "IBM Voice Type" languages Vocabels file
RTS = CA-Realizer runtime library
RTS = Mime: application/x-rtsl
RTS = RealAudio's RTSL document
RTSL = Real document
RTT = Ragtime file
RTX = Mime: application/rtf
RTX = Mime: text/richtext
RTX = Text document
RU = Javasoft Jre 1.3 lib file
RUL = Expert System Rule
RUL = Rules (Echo-conference)
RULE = (MAC FILE_TYPE) Microsoft Rules File
RUN = PC Tools for Win batch file
RUS = Russian text
RV = Mime: video/vnd.rn-realvideo
RV = RealVideo video
RVP = Microsoft Scan Configuration file
RVW = ReVieW
RWS = Borland C++ Resource Workshop Symbol file
RWX = Criterion RenderWare script/extruded text
RWX = MEME Shape File
RWX = Netscape Live 3D; see FLR
RWZ = MS OutlookXP Internet Settings
RX = Dos7 file
RXD = Reflex datafile
RXH = Reflex Database Help File
RXML = Roxen Macro Language
RXN = MDL Reaction format
RXN = Mime: chemical/x-mdl-rxn
RXN = Mime: chemical/x-mdl-rxnfile
RXR = Reflex Report
RXS = Reflex Database Screen Driver
RXX = RAR compressed files from a multi-volume archive (xx = a number from 01 to 99)

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Universal dump-utility for non-destructive dump/list/search string etc

Select Extension by starting letter:

A- B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U -

V- W - X - Y - Z - OTHER - Allowed chars in Filenames - what is an extension?


If you find an extension missing, write! No guarantee given for completeness or correctness. If you feel an extension is outdated, write!
Authors and retailers: it is in the interest of us all and our customers to avoid the double use of extensions! Please help us keep this compilation up todate!
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Any questions for not listed extensions or "what program opens xxx":
Any other questions, remarks, praise, flaming or reproach:
Compilation Copyright (c) 2002 R.Bitsch, Compilation Copyright (c) 2009,2010 R.Cooper-Bitsch